This project will use data from the 1993, 1997, and 2001 Robert Wood Johnson Foundation Employer Health Insurance Surveys to study how changes in health care markets have affected access to insurance coverage for two vulnerable populations: workers in low wage businesses and workers employed in rural areas. Specifically, the project will use the three employer surveys to assess the effects of health care market structure on employer decisions to offer insurance the benefits and types of plans offered, and the out-of-pocket cost burden for these populations. The project also will examine whether the structure of the local health care safety net affects employers' offers of insurance of insurance, providing a unique test of the "crowd out" hypothesis from the perspective of employers. Lastly, the project will develop a simulation model to predict the effect of varying market structure on the distribution of employment-based coverage and on out-of-pocket costs for workers in low wage businesses and rural workers.